build(deps): bump documents.js to 1.91.6

Triggered instantly via repository_dispatch when documents.js published its own release,
rather than waiting for the next scheduled Dependabot scan.

Author: github-actions[bot]

package.json

@@ -72,7 +72,7 @@
   "packageManager": "pnpm@11.6.0",
   "dependencies": {
     "commander": "^15.0.0",
-    "documents.js": "^1.91.0",
+    "documents.js": "^1.91.6",
     "ink": "^7.1.1",
     "ink-text-input": "^6.0.0",
     "odf.js": "^2.4.1",